"Anthracosis is a form of pneumoconiosis seen in coal workers, although other environmental factors such as cigarette smoke, air pollution and biomass fuels used extensively for cooking and home heating are also known to cause anthracosis.1–6 The terms “hut lung” or “domestically acquired particulate lung disease” have been used to describe the condition.7 A diagnostic feature in anthracosis is the black-colored deposits along the airway or lymph nodes. Problems caused by chronic exposure to biomass smoke and other particulates, such as dust or silicates from food grinding, are becoming more relevant in the western world due to immigration.7,8 Individuals may develop both physical and radiologic abnormalities of the lung presenting as chronic obstructive or fibrotic lung disease due to chronic exposure to smoke and particulates. Recent estimates attribute 1.5 to 2 million deaths per year worldwide to indoor air pollution, most of them (1 million) occurring in children younger than 5 years due to acute respiratory infections, but also in women due to chronic obstructive pulmonary disease and lung cancer."

"Our patient had a recent history of tuberculosis and a life-long history of exposure to wood-stove soot. An important question is, which came first? Tuberculosis can remain dormant in the body for decades. Dust deposition and scar formation are common findings in old lymphadenitis due to tuberculosis; therefore, one can argue that the inflammation induced by tuberculosis in the mediastinal lymph nodes may be the inciting stimulus for the final mass in this patient. However, the converse may be the case; environmental exposure to wood soot may be an immunosuppressive event in which the host’s cellular immunity action is diverted to engulfing anthracosis leading to impairment of respiratory defenses against mycobacteria."

The use of biomass as a cooking fuel was found to be significantly associated with a high prevalence of active tuberculosis(OR = 3.56, 95% CI: 2.82-4.50). The prevalence remained large and significant even after analyzing separately for men (OR = 2.46) and women (OR = 2.74) and for urban (OR = 2.29) and rural areas (OR = 2.65). Fifty-one percent of prevalence of active tuberculosis is attributable to cooking smoke in the age group 20 years and above.

BACKGROUND:Studies, particularly from low-income and middle-income countries, suggest that exposure to smoke from household air pollution (HAP) may be a risk factor for tuberculosis. The primary aim of this study was to quantify the risk of tuberculosis from HAP and explore bias and identify possible causes for heterogeneity in reported effect sizes.

METHODS:A systematic review was conducted from original studies. Meta-analysis was performed using a random effects model, with results presented as a pooled effect estimate (EE) with 95% CI. Heterogeneity between studies was assessed.

RESULTS:Twelve studies that considered active tuberculosis and reported adjusted effect sizes were included in the meta-analyses. The overall pooled EE (OR, 95% CI) showed a significant adverse effect (1.43, 1.07 to 1.91) and with significant heterogeneity between studies (I(2)=70.8%, p<0.001). When considering studies of cases diagnosed microbiologically, the pooled EE approached significance (1.26, 0.95 to 1.68). The pooled EE (OR, 95% CI) was significantly higher among those exposed only to biomass smoke (1.49, 1.08 to 2.05) when compared with the use of kerosene only (0.70, 0.13 to 3.87). Similarly, the pooled EE among women (1.61, 0.73 to 3.57) was greater than when both genders were combined (1.39, 1.01 to 1.92). There was no publication bias (Egger plot, p=0.136). Significant heterogeneity was observed in the diagnostic criteria for tuberculosis (coefficient=0.38, p=0.042).

CONCLUSIONS:Biomass smoke is a significant risk factor for active tuberculosis. Most of the studies were small with limited information on measures of HAP.

• The Surgeon General has determined that there is no safe level of exposure to ambient smoke!

• If you smell even a subtle odor of smoke, you are being exposed to poisonous and carcinogenic chemical compounds!

• Even a brief exposure to smoke raises blood pressure, (no matter what your state of health) and can cause blood clotting, stroke, or heart attack in vulnerable people. Even children experience elevated blood pressure when exposed to smoke!

• Since smoke drastically weakens the lungs' immune system, avoiding smoke is one of the best ways to prevent colds, flu, bronchitis, or risk of an even more serious respiratory illness, such as pneumonia or tuberculosis! Does your child have the flu? Chances are they have been exposed to ambient smoke!